Question

4 pens cost $2.80.
a) How much does 1 pen cost?
b) How much do 3 pens cost?

Answer 1

$0.70/pen; 3 pens for $2.10.

Explanation:

(a) Find the unit rate (cost per pen):

$2.80

----------- = $0.70/pen

4 pens

(b) Find the cost of 3 pens. To do this, mult. the unit rate by 3:

$0.70

----------- * 3 pens = $2.10

pen

Answer 2

It is 70 cents per pen because to find one pen, you do $2.80 divided by 4. To find three pens, you times the answer of 2.80 divided by 4, which is 0.70, by 3.